1. Field of the Invention
This invention relates to a method of producing a foam product and a product of the type which is made into blocks and into which cut flowers are pushed for support, transport and storage and use.
2. Description of the Prior Art
The use of phenol-formaldehyde (PF) or urea-formaldehyde (UF) foamed products as supports for cut flowers have been in common usage in the floral industry for many years. Either of the described foam products requires vigorous acid catalyzed conditions to transform the PF or UF resin (with surfactant, wetting agent, blowing agent, and color) into foam which foam may vary in density from 1.0 to 2.0 lb./ft.sup.3. A low density foam product is desirable for fragile flowers while a higher density foam product is suitable for heavy flowers or dry flowers. Foam properties desired are rapid wettability, good water retention, proper color, a crisp texture and ease of flower penetration, with good support and retention of the flower stems by the foam. The usual practice is to add a flower preservative to the water which the foams imbibes.
The U.S. Pat. to Smithers, No. 2,753,277 describes an absorbent material for floral arrangements wherein the foam is provided with a layer of wetting agent on the exterior to carry water into the interior of the foam mass. The foaming process is described as vigorous, and would deteriorate the flower preservative and bacteriocide.
The U.S. Pat. to Palombo, No. 3,049,444 discloses a foamed cellular synthetic material impregnated with a wetting agent and wherein the foam mass is provided with interior passages with a wetting agent disposed along the passages. The process has the same adverse affects as Smithers.
The U.S. Pat. to Jackson, Jr., No. 3,101,242 discloses a process of making flexible absorbent material wherein the foam mass prepared in accordance with Smithers U.S. Pat. No. 2,753,277 is compressed, bleached, leached to remove water soluble chemicals and treated with a wetting agent to increase its absorptive capacity.
The U.S. Pat. to Palombo, No. 3,697,457 describes a self wetting phenolic foam product wherein when making the foamed product, the wetting agents are mixed with the resin prior to foaming in seperate additions to obtain faster wetting and maximum water absorption in the foamed product.
The foaming condition as described for these prior art foam products including those disclosed by Smithers, the Palombo patents and Jackson are severe and decompose or char many flower preservatives, such as bacteriocides, sucrose, glucose and the like which would be incorporated into the resin prior to foaming.
The process for producing my foam product takes place under mild foaming conditions wherein sucrose, glucose and other sacchoridic materials as well as bacteriocides can be introduced into the resin prior to foaming. The foam appearance of the newly discovered composition in the absence of color additives exhibits no evidence of charring or decomposition of the preservative additive. The unusually mild foaming condition of my process, namely low concentration of acid catalyst, and longer curing time are beneficial in the preparation of a new floral foam composition with preservatives carried thereby. The desired product is described in "The Greenhouse Environment" by J. W. Mastalers, John Wiley & Sons (1977) at pp. 573-580.